MIAMI (AP) — Lined up in front of their dugouts, all wearing No. 42 on Jackie Robinson Day, the Washington Nationals and Miami Marlins stood for a moment of silence to honor bombing victims at the Boston Marathon.

What began as an annual celebration to salute the man who broke baseball’s color barrier 66 years ago turned somber after a pair of explosions near the finish line in Boston — about a mile from Fenway Park — killed at least three people and injured more than 140 on Monday.

Hours later, Major League Baseball went on with ceremonies for the fifth Jackie Robinson Day at stadiums all over the country and north of the border in Toronto.

“Our thoughts and prayers are with everyone affected by this horrible occurrence and we are monitoring the situation,” MLB spokesman Pat Courtney said in a statement. “The safety of everyone that comes to our ballparks is always our top priority and we will continue to do everything to ensure a safe environment for our fans.”

There were moments of silence before each of the seven night games. At Great American Ball Park in Cincinnati, President Barack Obama’s remarks to the nation were shown on the video board while the Phillies were taking batting practice.

“I think everyone was thinking about it,” said Philadelphia outfielder Ben Revere, who taped the message “PRAY for Boston” on his glove. “It hurts to see something like that happen.”

The game between the Boston Red Sox and Tampa Bay Rays started at 11:05 a.m. on Patriots Day in Massachusetts and ended about an hour before the bombings. Fans near Fenway Park, some who had recently exited the game, could hear the explosions.

All the teams in action were asked to wear Robinson’s number, retired throughout baseball in 1997. Yankees closer Mariano Rivera is the only active player who still wears the number, and he has said he is retiring after this season.

Teams that didn’t play on Monday planned to pay tribute to Robinson on Tuesday.

Robinson’s debut with the Brooklyn Dodgers on April 15, 1947, is drawing special attention this year with the release of the film “42,” which went into wide release last weekend.

Robinson’s widow, Rachel, along with the couple’s daughter, Sharon, and son, David, were introduced before the Dodgers played the Padres in Los Angeles.

In Minnesota, Twins first baseman Justin Morneau saw a screening of the movie in spring training and was pleasantly surprised to see brief footage of himself running onto the field during some of the stock shots of players paying homage to Robinson by wearing his No. 42.

“I wasn’t expecting it, so it was pretty cool,” Morneau said. “Just quick running across the screen, but to see yourself in a movie of that importance is pretty cool.”

The Rays had a special screening, too.

More than 100 players and other club employees watched the film at a theater in Port Charlotte, Fla., the Rays’ spring training site, “and I think a lot of guys walked away with a greater appreciation” of Robinson’s contribution, manager Joe Maddon said before the Rays lost 3-2 to the Red Sox.

Maddon said Robinson’s debut helped lead to the broader civil rights movement.

“I still don’t think people understand how much it plays into the Martin Luther King situation,” he said. “The revolution that occurred at that particular moment, it mattered. That had to happen first to set that whole thing up.

“So when you’re talking about Jackie Robinson, I don’t think people realize the significance and really courage that went behind that, and in the movie it points that out — the courage to not fight back, to be able to win over that particular mindset to be able to make all of this work,” he added.

Red Sox manager John Farrell said baseball “reflects society in so many ways, whether it’s the color barriers being broken down. In our clubhouse you’ve got six or seven countries coming together. As a group of 25, you look to not only co-exist, but (recognize) the individuality of everyone in there.

“Certainly, the Robinson family and certainly Jackie himself may be one of the most significant situations in our country’s history,” Farrell said, “breaking down segregation to the point of inclusion and I think that happens in the game today.”

The movie “42″ earned an estimated $27.3 million over the weekend, according to Warner Brothers, its distributor.

The subject’s popularity extends to the sale of licensed sports merchandise. Fanatics.com, a large online retailer of those items, said sales of Jackie Robinson gear on its site since the season began increased by more than 1,000 percent over the same time period last year.

In Miami, the ceremonial first pitch was thrown out by Norman Berman, the ballboy for the Brooklyn Dodgers the year Robinson was a rookie.

The 84-year-old Berman lives in nearby West Palm Beach. He was the Dodgers’ 19-year-old ballboy in 1947 when the team reached the World Series.

Berman said Robinson befriended him, played catch with him and gave tips on how to make a double-play pivot.

“He was a wonderful person,” Berman said. “I learned something from him — when you go through tough times, you’ve got to stay positive. I don’t think most of the ballplayers who came after him would have been able to be the first black ballplayer, because they couldn’t do what he did.”